肝素及血小板激活因子对牛卵母细胞体外受精的影响

Effects of Heparin and Platelet Activating Factor on the In Vitro Fertilization of Bovine Oocytes

关键词:  肝素  血小板激活因子  公牛  卵母细胞  体外受精

Key words:  heparin platelet activating factor (PAF)  bulls  oocytes  in vitro fertilization (IVF)

摘要:

在受精液中添加不同浓度的肝素(2,6,18,54,162,486mg/L)均能明显提高牛卵母细胞的受精分裂率(分别为83.6,84.9,85.7,89.2,84.5和90.2%,比对照组73.6%,P<0.05)和卵裂指数(授精后44~46h大于2-细胞的卵裂数占卵裂总数的百分率,分别为85.7,85.0,89.9,87.9,87.4和85.5%,比对照组57.6%,P<0.01。然而,卵母细胞的囊胚发育率则仅当肝素浓度等于或大于18mg/L时才明显提高(21.1,25.0,36.2,39.7,38.4和37.0%,比对照组24.7%,P<0.05)。提高受精液中的肝素浓度(从5到50mg/L)能提高来自不同公牛精液的体外受精效果(以分裂率和囊胚发育率评定),但不能消除公牛精液间体外受精效果的原有差异。在受精液中添加100μg/L的血小板激活因子(PAF)明显提高卵母细胞的囊胚发育率(41.7%,比34.4%,P<0.05),但对卵母细胞的分裂率及囊胚孵化率无明显影响。当卵母细胞受精在含10μg/LPAF的受精液中时,可获得较高的囊胚孵化率(95.6%)。表明适当提高受精液中的肝素浓度或添加适当浓度的PAF能提高牛卵母细胞体外受精后的胚胎发育能力。肝素和PAF的这一效应可能是通过促进精子的获能和活力而起作用的,与公牛的个体无关。

Abstract:

Effects of heparin and platelet activating factor (PAF) on the in vitro fertilization of bovine oocytes (IVF) were examined. Addition of heparin to the fertilization medium at all the concentrations tested (2, 6, 18, 54, 162, 486 mg/L) resulted in a significant increase in the cleavage rate of oocytes (83.6, 84.9, 85.7, 89.2, 84.5 and 90.2% resp. vs 73.6%, P<0.05) and the proportion of zygotes beyond the 2-cell stage (85.7, 85.0, 89.9, 87.9, 87.4 and 85.5% vs 57.6%,P<0.01). However, the frequency of oocytes developing to the blastocyst stage did not increase untill the concentration of heparin equalled or exceeded 18 mg/L (21.1, 25.0, 36.2,39.7,38.4and 37.0% resp. vs 24.7%, P<0.05). Increasing heparin concentration from 5 mg/L to 50 mg/L resulted in a significant increase in the cleavage rate and blastocyst development of oocytes fertilized with sperm from all of the three bulls, but could not delete the variation among bulls in their contribution to IVF. The addition of 5 mg/L PAF to the fertilization medium resulted in a significant increase in the frequency of oocytes developing to the blastocyst stage (41.7% vs 34.4%, P<0.05), but not in the cleavage rate of oocytes and the proportion of blastocysts hatched. A high percentage of blastocysts hatched was achieved when IVF took place in the presence of 10 μg/L PAF. Appropriate elevation of heparin concentrations and addition of PAF to the fertilization medium can improve the embryonic development of bovine oocytes after IVF. This action of heparin and PAF may be mediated by facilitating the capacitation and motility of sperm and is independent of bulls.